On a number line, a number, b, is located the same distance from 0 as another number, a, but in the opposi
number b varies directly with the number a. For example b = 23 when a = -23. Which equation represents
variation between a and b?
b= -a
-b = -a
b-a = 0
B(-a) = 0

Use the normal approximation to the binomial distribution to answer this question. fifteen percent of all students at a large university are absent on mondays. if a random sample of 12 names is called on a monday, what is the probability that four students are absent?

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?